EMECH SOLUTIONS

Relays Enable Solar Powered Systems

As environmental concerns and sustainability become more important, interest is growing in solar power generation. Tyco Electronics supplies a number of core components that may be used in PhotoVoltaic (PV) solar modules, both in domestic and commercial installations.



PV solar energy systems typically consist of a generator and a power inverter with a connection to the public power grid. The connection is bi-directional, allowing power to be taken from, or fed to, the grid. Such an arrangement is subject to special standards and regulations to ensure safety and prevent system damage.

Safety measures require an automatic switching unit with a circuit break function between the generator and feed-in point. Switching units must comply with DIN standard V VDE V 0126-1-1; the most important part of this standard is the need for a contact gap larger than 1.5mm at each switched pole.

For PV systems with galvanic isolation and single-phase AC feed-in, at least two normally open relay contacts are needed, one each for the phase and neutral lines. In PV systems with no galvanic isolation, both of the switches mounted in series must be electromechanical components.

Tyco Electronics offers a variety of solutions for solar generation systems from its RM, 041083 and PCFN product families. The PCFN Solar, for instance, is a normally open monostable relay that occupies a printed circuit area of just 490mm² and dissipates very little power. It has a continuous contact rating of 26A and the required 1.5mm contact gap. Pull-in power of 1.5W is required for 0.1s for secure operation, after which the power of the coil can be reduced to a hold level of 200mW.

Although electromechanical relays are already mandatory for interconnection to the power grid, they are also useful for coupling the PV generator to the inverter electronics. Use of a component such as the Tyco Electronics EV 200 allows implementation of special features such as remote on/off switching, service disconnection and reversible emergency shutdown in the event of a fault. The EV 200 can accommodate voltages up to 900VDC and current requirements up to 200A.

Relays may also be used in PV systems for interface functions and for internal monitoring, test and diagnostic purposes. Relays with large contact gaps such as the RP920145 are often required for such applications.

Features: PCFN Solar

• One normally open contact
• 26A current rating
• Rated voltage 277VAC
• Breaking capacity 7,200VA
• Contact gap larger than 1.5mm
• Coil-to-contact dielectric strength 4000V
• Clearance/creepage 6.1mm
• Operation requires 1.5W for 100ms
• 200mW holding power

Features: EV 200

• One normally open bridging contact
• 200A current rating
• Rated voltage 320V (900V maximum)
• 2,000A breaking capacity
• Contact gap larger than 1.3mm
• Coil voltage 9VDC to 36VDC
• Coil-to-contact dielectric strength 2,000V
• Operation requires 1.5W for 100ms
• 200mW holding power

For further information, including the Tyco Solar Flyer, please click here